The invention relates to an omnidirectional multiple-band antenna which can be simultaneously connected to a plurality of transceivers.
In practice, such an antenna has consisted up to the present of a rod antenna to which the transmitters are connected via a resistance network because of the required mutual isolation. There are, however, large losses in such a system and, consequently, bigger transmitters which cause heat transfer problems are required.
In parctice a rod antenna has also been used with a power amplifier connected to it for processing the sum of the signals to be transmitted. This imposes high requirements on the linearity of the amplifier which entails great expense.
Alternatively, two separate antennas have been used in practice, a transmitting antenna and a receiving antenna. Apart from the same problems as for the above-mentioned applications, two antennas must be erected instead of one antenna, which is not attractive from the operational point of view.